Arthritis
Arthritis is inflammation of one or more of your joints. The main symptoms of arthritis are joint pain and stiffness, which typically worsen with age. The two most common types are osteoarthritis and rheumatoid arthritis.
Osteoarthritis is usually caused by normal wear and tear, while rheumatoid arthritis is an autoimmune disorder. Other types of arthritis can be caused by uric acid crystals, infections or even an underlying disease — such as psoriasis or lupus.
Treatments vary, depending on the type of arthritis. The main goals of the treatments are to reduce symptoms and improve quality of life.
SYMPTOMS
The most common signs and symptoms of arthritis involve the joints. Depending on the type of arthritis you have, your signs and symptoms may include:
CAUSES
The pain associated with arthritis is caused by joint damage. Joints are made up of the following parts:
- Cartilage. A hard, but slick, coating on the ends of bones, cartilage allows bones of the joint to slide smoothly over each other.
- Joint capsule. This tough membrane encloses all the joint parts.
- Synovium. This thin membrane lines the joint capsule and secretes synovial fluid, which lubricates the joint and nourishes the cartilage.
- How arthritis damages joints
- The two main types of arthritis damage joints in different ways.
- Osteoarthritis. In osteoarthritis, wear-and-tear damage to cartilage can result in bone grinding directly on bone, which causes pain and restricts movement. This wear and tear can occur over many years, or it can be hastened by a joint injury or infection.
- Rheumatoid arthritis. In rheumatoid arthritis, the body’s immune system attacks joints and inflames the synovium, causing swelling, redness and pain. The disease can eventually destroy cartilage and bone within the joint.
RISK FACTORS
Risk factors for arthritis include:
- Family history. Some types of arthritis run in families, so you may be more likely to develop arthritis if your parents or siblings have the disorder. Your genes can make you more susceptible to environmental factors that may trigger arthritis.
- Age. The risk of many types of arthritis — including osteoarthritis, rheumatoid arthritis and gout — increases with age.
- Sex. Women are more likely than are men to develop rheumatoid arthritis, while most of the people who have gout are men.
- Previous joint injury. People who have injured a joint, perhaps while playing a sport, are more likely to eventually develop arthritis in that joint.
- Obesity. Carrying excess pounds puts stress on joints, particularly your knees, hips and spine. Obese people have a higher risk of developing arthritis.
TESTS AND DIAGNOSIS
Depending on the type of arthritis suspected, your doctor may suggest some of the following tests.
To obtain a sample of your joint fluid, your doctor will cleanse and numb the area before inserting a needle in your joint space to withdraw some fluid.
IMAGING
These types of tests can detect problems within your joint that may be causing your symptoms. Examples include:
- X-rays. Using low levels of radiation to visualize bone, X-rays can show cartilage loss, bone damage and bone spurs. X-rays may not reveal early arthritic damage, but they are often used to track progression of the disease.
- Computerized tomography (CT). CT scanners take X-rays from many different angles and combine the information to create cross-sectional views of internal structures. CTs can visualize both bone and the surrounding soft tissues.
- Magnetic resonance imaging (MRI). Combining radio waves with a strong magnetic field, MRI can produce more-detailed cross-sectional images of soft tissues such as cartilage, tendons and ligaments.
- Ultrasound. Using sound waves to create images of both hard and soft tissues within the body, ultrasound can help determine needle placement if your doctor wants to withdraw fluid from your joint or inject medicine.